706
FXUS65 KBYZ 140313
AFDBYZ
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
913 PM MDT WED MAY 13 2026
KEY MESSAGES
- ISOLATED HIGH-BASED THUNDERSTORMS LATE THIS AFTERNOON/EVENING
COULD PRODUCE STRONG/ERRATIC WIND GUSTS.
- PACIFIC FRONTAL PASSAGE WILL BRING STRONG WEST WINDS TONIGHT
THROUGH THURSDAY; 60+ MPH GUSTS LIKELY ALONG THE US-191 CORRIDOR
FROM BIG TIMBER TO JUDITH GAP, AND 40+ MPH GUSTS ACROSS THE
REGION. WINDY AND DRY CONDITIONS COULD CAUSE RAPID FIRE SPREAD.
- DRY AND STILL BREEZY FRIDAY.
- TRENDING COOLER WITH AN INCREASING CHANCE OF PRECIPITATION
(INCLUDING MOUNTAIN SNOW) THIS WEEKEND.
DISCUSSION
THROUGH NEXT WEDNESDAY...
SATELLITE IMAGERY SHOWS AN APPROACHING PACIFIC TROF OVER WA/OR AND
A DOWNSTREAM RIDGE AXIS OVER EASTERN MT, AND HEIGHTS ARE BEGINNING
TO FALL OVER OUR FORECAST AREA. A SURFACE COLD FRONT IS LOCATED
FROM FAR WESTERN MT TO SOUTHWEST ID AS OF 17Z, AND MESOANALYSIS
SHOWS A REGION OF HEALTHY PRESSURE FALLS FROM NEAR BUTTE TO
SALMON. AS A RESULT, WE ARE SEEING EASTERLY WINDS AND NOT QUITE
READY TO MIX THE SW FLOW ALOFT. WEAK CONVECTION HAS DEVELOPED IN
CENTRAL ID BUT OUR WEST IS STILL CAPPED. OVERALL, WE ARE STILL A
FEW HOURS FROM SEEING THE RISK OF T-STORMS REACH US. EXPECT THAT
TO BE ~21Z. SPC HAS EXPANDED THE SLIGHT RISK FOR SEVERE T-STORMS
TO INCLUDE AREAS FROM RED LODGE TO LAVINA WESTWARD, AND A MARGINAL
RISK EXTENDS EASTWARD TO MILES CITY & BROADUS. THIS MORNING'S
HREF SHOWS BEST PROBS FOR CONVECTIVE HIGH WINDS FROM BILLINGS
WESTWARD AND NORTHWARD, AS FAR EAST AS NORTHERN ROSEBUD.
OBVIOUSLY, THE RISK OF STRONG/ERRATIC WINDS WILL EXIST WITH ANY
WEAK T-STORM OR SHOWER, AS THE BOUNDARY LAYER WILL BE DEEPLY MIXED
AND DRY. NO CHANCE OF ANYTHING BUT TINY HAIL TODAY.
FOLLOWING THE CONVECTIVE WIND POTENTIAL (THERE MAY BE MULTIPLE
ROUNDS UNTIL THE FRONT ARRIVES FROM THE WEST THIS EVENING) WE
TRANSITION TO SYNOPTICALLY-DRIVEN/STRONG/POST-FRONTAL WEST WINDS.
SUBSIDENCE ARRIVES IN OUR FAR WEST BY 06Z AND IS OVER MOST OF OUR
CWA BY 12Z. CONFIDENCE IS HIGH FOR WINDY CONDITIONS ACROSS THE
AREA THROUGH TOMORROW, BUT THERE REMAINS UNCERTAINTY WITH
MAGNITUDE OF HIGHEST GUSTS. GFS CONTINUES TO BE STRONGEST WITH MID
LEVEL WINDS AND THE EC WEAKER, AND HISTORICALLY SOME SORT OF
BLEND OF THE TWO VERIFIES BEST. THE 12Z GFS HAS ACTUALLY TRENDED A
BIT WEAKER SO THERE IS SOME CONFIDENCE THERE. EXISTING WIND
HIGHLIGHTS LOOK GOOD AND WILL MAKE NO CHANGES, AND WILL ALSO MAKE
NO FURTHER ADDITIONS IN COVERAGE. WITH THE GREATEST 850-700MB
WINDS OCCURRING BEFORE 18Z TOMORROW, DO NOT SEE A NEED TO EXPAND
EAST OF YELLOWSTONE/MUSSELSHELL AS THERE SHOULDN'T BE ENOUGH MIXED
WIND DURING PEAK HEATING HOURS, BUT THIS WILL NEED TO BE
MONITORED. THE IMMEDIATE WIND RISK IS WITH CONVECTION BETWEEN
21-04Z. HEADS UP IF YOU HAVE OUTDOOR PLANS THIS EVENING.
REGARDING FIRE WEATHER, MUCH OF THE REGION HAS GREENED UP
SUFFICIENTLY TO PREVENT A SIGNIFICANT RISK OF GRASS FIRES, BUT
THERE ARE PATCHES THAT ARE DRIER, AND LARGER FUELS ARE REPORTING
BELOW NORMAL FUEL MOISTURES. PLEASE TAKE CARE TO NOT SPARK A FIRE
WITH THE DRY AND WINDY CONDITIONS THROUGH TOMORROW! IN FACT, IT
WILL REMAIN BREEZY (THOUGH NOT AS STRONG AND A BIT COOLER)
FRIDAY. T-STORMS THIS EVENING WILL PRODUCE ONLY SPOTTY LIGHT
RAINFALL.
LOOK FOR TEMPS IN THE MID 60S TO MID 70S TOMORROW THROUGH
SATURDAY, WITH MUCH LESS WIND AND HIGHER HUMIDITIES BY THE
WEEKEND.
THINGS GET MORE INTERESTING THIS WEEKEND AS A STRONGER TROF W/
MUCH LOWER HEIGHTS DROPS THROUGH THE NORTHERN ROCKIES. THIS WILL
BRING COOLER TEMPS AND INCREASING PRECIP CHANCES, WITH HIGH
CONFIDENCE, BUT DETAILS REMAIN HIGHLY UNCERTAIN. AN OPEN TROF WILL
MEAN LOWER PRECIP TOTALS WHILE A CLOSED LOW DEVELOPING OVER WY
WOULD RESULT IN HEAVIER UPSLOPE PRECIPITATION. EITHER WAY, TEMPS
ALOFT WILL BE COLD ENOUGH SUCH THAT MOUNTAINS WILL SEE SNOWFALL.
IF A MORE DYNAMIC SYSTEM MATERIALIZES WE COULD ALSO BE LOOKING AT
WET SNOW FOR THE FOOTHILLS. LOOK FOR TEMPS SOMEWHERE BETWEEN THE
MID 40S AND NEAR 60F SUNDAY & MONDAY (WARMEST EAST). CONSENSUS IS
FOR TEMPS BACK TO THE 60S TUESDAY & WEDNESDAY, BUT THERE IS
POTENTIAL FOR ANOTHER TROF TO ARRIVE BY THEN. GENERALLY SPEAKING,
THE WEATHER PATTERN IS LOOKING ACTIVE AND COOLER THROUGH THE FIRST
HALF OF NEXT WEEK.
AN INTERESTING SIDE NOTE. WHEN THE BILLINGS AIRPORT REACHES 90F
TODAY, IT WILL HAVE SEEN 50F IN JAN, 60F IN FEB, 70F IN MAR, 80F
IN APR AND 90F IN MAY. WHILE THESE TEMPS ARE NOT UNCOMMON IN ANY
OF THESE MONTHS, IT OCCURRING IN ALL 5 MONTHS HAS HAPPENED ONLY 4
OTHER TIMES SINCE 1934, MOST RECENTLY IN 1992.
JKL
AVIATION
03Z UPDATE...
DRY THUNDERSTORMS HAVE TAPERED OFF THIS EVENING AND HIGH WINDS
WILL PICK UP MIDNIGHT THROUGH MID DAY THURSDAY. WIDESPREAD GUSTS
TO 40KTS ARE POSSIBLE WITH HIGHER GUSTS FOR KLVM/K6S0/K3HT WHERE
THERE IS A 40% CHANCE FOR GUSTS TO 60 KTS THROUGH THE MORNING. TS
PRELIMINARY POINT TEMP/POPS
THU FRI SAT SUN MON TUE WED
-----------------------------------------------------------
BIL 052/075 047/072 041/071 041/050 036/051 035/063 042/064
20/N 00/N 00/B 55/W 54/W 21/B 23/T
LVM 042/070 040/068 036/065 032/042 028/047 029/058 035/062
30/N 00/N 03/T 88/T 75/T 22/T 23/T
HDN 052/075 045/073 038/073 041/053 035/051 033/063 039/064
20/N 00/N 00/B 35/W 65/W 21/B 23/T
MLS 052/074 046/072 039/073 044/057 036/050 034/061 040/064
50/N 00/N 00/B 44/W 55/W 31/B 22/W
4BQ 052/073 042/072 038/074 045/056 036/047 033/059 039/062
40/N 00/U 00/B 33/W 66/W 21/B 12/W
BHK 050/073 043/071 036/072 043/058 034/046 031/058 037/062
20/N 00/N 00/B 45/W 66/W 32/W 12/W
SHR 045/075 039/072 035/072 037/049 030/045 028/058 034/061
20/N 00/U 00/B 38/T 87/T 22/T 13/T
BYZ WATCHES/WARNINGS/ADVISORIES
MT...HIGH WIND WARNING IN EFFECT UNTIL 9 PM MDT THURSDAY FOR ZONES
29-34-42-63-141-172-228-235.
SEVERE THUNDERSTORM WATCH 201 IN EFFECT UNTIL 11 PM MDT THIS
EVENING FOR ZONES 29>31-56>58-67-138-139-169>171-173-235.
HIGH WIND WARNING IN EFFECT UNTIL 6 AM MDT THURSDAY FOR ZONES
56-139-170.
HIGH WIND WARNING IN EFFECT UNTIL 10 PM MDT THIS EVENING FOR
ZONE 64.
WIND ADVISORY IN EFFECT UNTIL 9 PM MDT THURSDAY FOR ZONES
65-66.
HIGH WIND WARNING IN EFFECT UNTIL 6 PM MDT THURSDAY FOR ZONE
68.
WY...NONE.
WEATHER.GOV/BILLINGS
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